“There are four Singaporean and Malaysian companies,” she told reporters on Friday after a meeting with other ministers to discuss wildfire mitigation.

Siti named the palm oil companies in question. Three of them, namely Sime Indo Agro, Rafi Kamajaya Abadi and Sukses Karya Sawit, are West Kalimantan-based subsidiaries of Malaysian conglomerates. A plantation owned by PT Hutan Ketapang Industri, which is owned by a Singaporean firm, was also sealed.

Lee Yeow Seng, the son of the CEO of IOI Corporation, which owns Sukses Karya Sawit, is reportedly the husband of Malaysian Energy, Technology, Science, Climate Change and Environment Minister Yeo Bee Yin, who previously said Siti was “in denial” for questioning her complaint about the haze.

Smog in Malaysia has turned into a blame game between authorities of the neighboring countries over the past week, with Malaysia saying wildfires in Indonesia were responsible for the choking haze that led to the temporary closure of hundreds of schools. The Malaysian government sent half a million face masks to Sarawak this week.

Most recently, Malaysian Prime Minister Mahathir Mohamad was planning to write to his Indonesian counterpart President Joko “Jokowi” Widodo to express his concern over transborder haze, according to Yeo.

Reuters, meanwhile, reported a spokeswoman for Jakarta-based Minamas Plantation, a Sime Darby unit that runs the group's Indonesian operations, had said it was not aware of its plantation having been sealed off and that it was monitoring its lands for hot spots.